Wind energy research covers a variety of different fields, e.g. aerodynamic control and design methods for turbine blades, electricity conversion, wind tunnel tests or wind farms and wind farm control. They all focus on the impact of the incoming wind to gain maximum power output of the wind turbine. The atmospheric application of the influence of a wind turbine on the turbulent wake flow was not in the focus of the wind energy research up to now. However, the flow deformation by wind turbines might influence the thermodynamics properties of the atmosphere in the lee of large wind farms. Therefore, it is necessary to investigate the effect of individual turbines on the atmosphere for different ambient thermal stratifications. Furthermore, the political decisions to place wind turbines also inland (or “onshore” in contrast to the huge “offshore” wind farms) request a detailed study of the interaction of the flow over heterogeneous terrain with wind turbines. Flow over forests and hills are just two examples for the very broad spectrum of possible terrain inhomogeneities.In this project, we propose a series of high-resolution numerical simulations to investigate the interaction of a wind turbine with the atmospheric boundary layer flow systematically for different thermal stratifications of the atmosphere. The simulations will be used to study how the wake flow behind the wind turbine is modified for different times of a day. In addition, the influence of flow across complex terrain on the wake will be explored. For this purpose, high-resolution parameterizations of the forces a wind turbine exerts on the atmospheric flow were already implemented in the numerical code and these parameterizations will be applied for the proposed numerical experiments.